城川城址位于內蒙古自治區鄂托克前旗城川蘇木東(dong)北。故城始建于唐開元十一年(nian)(nian)(723年(nian)(nian)),為唐代宥(you)州(zhou)城,主要安(an)置附唐的(de)突厥人。814年(nian)(nian)西夏(xia)復置宥(you)州(zhou),領長澤、延恩(en)二縣。在1227年(nian)(nian)被毀。
城(cheng)(cheng)川城(cheng)(cheng)址地(di)(di)(di)(di)處(chu)陜北黃土高原和內(nei)蒙古(gu)(gu)東(dong)(dong)南(nan)(nan)部毛(mao)烏素(su)沙(sha)地(di)(di)(di)(di)的(de)(de)(de)交接地(di)(di)(di)(di)帶(dai),地(di)(di)(di)(di)貌類型由黃土丘陵向沙(sha)地(di)(di)(di)(di)轉變,屬于(yu)中國北方(fang)生態過渡帶(dai)的(de)(de)(de)中段(duan)。古(gu)(gu)城(cheng)(cheng)地(di)(di)(di)(di)處(chu)東(dong)(dong)西(xi)(xi)狹長(chang)(chang)(chang)的(de)(de)(de)草(cao)(cao)灘(tan)地(di)(di)(di)(di)的(de)(de)(de)中心(xin),草(cao)(cao)灘(tan)地(di)(di)(di)(di)四周(zhou)均為由新(xin)月形沙(sha)丘鏈構(gou)成的(de)(de)(de)一望無際的(de)(de)(de)沙(sha)漠,草(cao)(cao)灘(tan)地(di)(di)(di)(di)地(di)(di)(di)(di)勢平(ping)坦,地(di)(di)(di)(di)下水(shui)位很高。古(gu)(gu)城(cheng)(cheng)平(ping)面(mian)形制呈長(chang)(chang)(chang)方(fang)形,東(dong)(dong)西(xi)(xi)長(chang)(chang)(chang)、南(nan)(nan)北窄,坐(zuo)北朝南(nan)(nan)。北墻(qiang)(qiang)長(chang)(chang)(chang)724米(mi),南(nan)(nan)墻(qiang)(qiang)長(chang)(chang)(chang)760米(mi),東(dong)(dong)墻(qiang)(qiang)長(chang)(chang)(chang)600米(mi),西(xi)(xi)墻(qiang)(qiang)長(chang)(chang)(chang)602米(mi),面(mian)積(ji)(ji)440000平(ping)方(fang)米(mi)。城(cheng)(cheng)墻(qiang)(qiang)由灰白色沙(sha)土夯筑而(er)成,結(jie)構(gou)堅實緊密。東(dong)(dong)、南(nan)(nan)、西(xi)(xi)三面(mian)各開一門(men),三門(men)均設甕(weng)城(cheng)(cheng)護衛。墻(qiang)(qiang)體保存(cun)較(jiao)好,墻(qiang)(qiang)上角樓(lou)、甕(weng)城(cheng)(cheng)、馬面(mian)歷歷可見,城(cheng)(cheng)垣(yuan)現(xian)存(cun)平(ping)均高度約8米(mi)。北面(mian)不設城(cheng)(cheng)門(men),建有(you)(you)高大的(de)(de)(de)夯土臺基,為敵樓(lou)遺(yi)(yi)跡。城(cheng)(cheng)外四周(zhou)修有(you)(you)護城(cheng)(cheng)河,痕(hen)跡明顯(xian),部分地(di)(di)(di)(di)帶(dai)至今仍可見積(ji)(ji)水(shui)。城(cheng)(cheng)內(nei)曾經一度被辟為耕(geng)地(di)(di)(di)(di),現(xian)已退耕(geng)還草(cao)(cao)。早年(nian)遍布陶、瓦殘片遺(yi)(yi)物。出土的(de)(de)(de)古(gu)(gu)代銅錢(qian)從西(xi)(xi)漢(han)到西(xi)(xi)夏(xia)、金代均可見到,唯以唐、宋的(de)(de)(de)錢(qian)幣(bi)數量多。
城(cheng)川(chuan)古城(cheng)所(suo)在的(de)位置正是漢代古奢延(yan)澤所(suo)在,鉆探結(jie)果表明(ming)城(cheng)址曾(ceng)遭到(dao)焚(fen)毀(hui)。
2006年(nian)5月,被國(guo)務院分布為第六(liu)批全國(guo)文(wen)物保護單位(wei)。